Combination soap and hydrogenated olefin sulfonate detergent bars

ABSTRACT

Soap and detergent bars prepared from a major proportion of soap and a minor proportion of hydrogenated olefin sulfonate containing from 10 to 24 carbon atoms in an amount sufficient to retain in suspension insoluble lime soaps resulting from use in hard water.

United States Patent Inventors Appl. No.

Gar Lok Woo Tlburon;

William Alan Sweeney, San Rafael, both of Calif.

Aug. 1 1, 1969 Sept. 2 l 1971 Chevron Research Company San Francisco, Calif.

Continuation-impart of application Ser. No. 748,I88, July 29, 1968.

COMBINATION SOAP AND I-IYDROGENATED OLEFIN SULFONATE DETERGENT BARS 5 Claims, No Drawings U.S.Cl 252/l6l,

InLCI Clld I/I2 Field of Search 252/161, I21; 260/5 l 3 [5 6] Relerences Cited UNITED STATES PATENTS 3,070,547 I2/l962 Chaffee 252/12I 3,332,874 7/l967 Coward et al 252/16] 3,332,880 7/I967 Kessler et al 252/l6l FOREIGN PATENTS l,l5l,052 5/1969 Great Britain 252/161 Primary Examiner-Herbert B. Guynn Assistant ExaminerWiIliam E. Schulz An0rneys-A. L. Snow, Frank E. Johnston and John Stoner,

ABSTRACT: Soap and detergent bars prepared from a major proportion oi soap and a minor proportion of hydrogenated olefin sulfonate containing from 10 to 24 carbon atoms in an amount sufficient to retain in suspension insoluble lime soaps resulting from use in hard water.

COMBINATION SOAP AND HYDROGENATED OLEFIN SULFONATE DETERGENT BARS CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of William Alan Sweeney and Gar Lok Woo US. application Ser. No. 748,188, filed July 29, 1968.

BACKGROUND OF THE INVENTION Lime soaps are formed by the reaction of a water-soluble soap usually the sodium salt of a fatty acid of 12 to 18 carbon atoms) with magnesium and/or calcium calcium ions as occur in hard water. The resulting calcium and/or magnesium slats are insoluble in water and a precipitate forms. This precipitate has s tendency to coagulate along with soap and direct to form lime soap curds. These curds then become attached to the surfaces of sinks, bathtubs, shower walls, and the like in an undesirable manner.

The calcium and magnesium slats of sulfated or sulfonated detergents are water soluble and hence do not form the insoluble curds as do soaps. For this reason, detergents have largely replaced soap in laundry applications. However for hand washing, soap bars are still preferred over detergent bars. This is true even though soap bars give lime soap curds in hard water and detergent bars do not. One reason for the continued preference for soap bars is the "feel" of a soap bar when in use.

The above soap bar and detergent bar drawbacks sometimes have been overcome by combining both soap and detergent in one bar, commonly called a combar." In such a bar, the soap component provides the desirable feel and the detergent component limits the curd formation. Surprisingly, not all detergents can be used in such combinations. At lime soap dispersing concentrations, some detergents have a sticky feel on the hands of the washer, other soften the resulting bar too much, and others detract from the oxidative stability of the bar. Some detergents must be used in such large quantities to prevent curd formation that the desirable soap properties are lost. Still other lime soap dispersants for use in combars are complex components, difficult and expensive to manufacture.

SUMMARY OF THE INVENTION In accordance with the present invention there are provided superior new soap and detergent bars comprising a major proportion of soap characterized as water-soluble salt of fatty acid having from about ID to 20 carbon atoms and a minor proportion of hydrogenated olefin sulfonate characterized as mixed sulfonates obtained by l. Sulfonating straight chain olefins containing from 10 to 24 carbon atoms with S0,, 2. Neutralizing and hydrolyzing the product of l, 3. l-lydrogenating from 50 to I percent of the unsaturated carbon-to-carbon double bonds in the product of 2, said hydrogenated olefin sulfonate being present in amounts of at least about of the total weight of soap and hydrogenated olefin sulfonate sufficient to retain in suspension the insoluble lime soaps resulting from use in hard water.

In general, the soap and detergent bars of this invention are obtained by combining soap and hydrogenated olefin sulfonate in a weight ratio of 40:60 to 99:] respectively, and forming said combination into a bar by conventional means such as milling an molding.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The soaps used in the compositions of this invention are any of the conventional soaps. These soaps are water-soluble salts of fatty acids having from about I0 to 20, preferably from 12 to 18, The usual water-soluble salt is the sodium salt; but other salts, such as the potassium or ammonium salts, may also be used, The fatty acid portion of the soap is a straight-chain carboxylic. acid. These acids are usually obtained by the saponification of fats, e.g. tallow or of oils, e.g. coconut oil. However,

suitable acids may also be obtained by oxidation of normal paratfins.

The hydrogenated olefin sulfonates are obtained by the catalytic hydrogenaton of olefin sulfonates. The term olefin sulfonates," as used in the present invention, defines the complex mixture obtained by the S0, sulfonation of straight-chain olefins containing 10 to 24 carbon atoms and subsequent neutralization and hydrolysis of the sulfonation reaction product. This complex mixture contains hydroxyalkane sulfonates and alkene sulfonates as its major components and a lesser proportion of disulfonated product.

While the general nature and the major components of the complex mixture is known, the specific identity and the relative proportions of the various hydroxy sulfonate and disulfonate radicals and double bond locations are unknown. Accordingly, a determination of the entire chemical makeup is exceedingly difficult and has not heretofore been successfully accomplished. The mixture is best defined by the general process used for producing it as herein described.

Optimum combar properties are exhibited by a composition obtained by hydrogenating an olefin sulfonate product which contains from about 25-75% by weight alkene sulfonates, from about 25-65% by weight hydroxyalltane sulfonates, and not more than 20 weight disulfonates. These optimum compositions are obtained by 80,: air sulfonation of C -C straight-chain olefins with S0,:air volume ratio of about 1:50-100, and an S0, :olefin mole ratio of l.05l.25:l followed by neutralization and hydrolysis of the sulfonation reaction product at temperatures of l4-250C. using one equivalent of base per mole of SO, consumed in the sulfonation step.

In addition to the straight-chain a-olefins from wax cracking, suitable olefin starting materials include straightchain a-olefins produced by Ziegler polymerization of ethylene, or internal straight-chain olefins prepared by catalytic dehydrogenation of normal parafl'ins, or by chlorinationdehydrochlorination of normal paraffins. The olefins may contain from 10 to 24 carbon atoms, usually l3 to 22 carbon atoms, per molecule. Olefin mixtures should have an average molecular weight of at least about 200.

The amount of SO, utilized in the sulfonation reaction may be varied but is usually within the range of 0.95 to 1.35 moles of $0; per mole of olefin and, preferably, in the range of IDS-1.25:1. Greater formation of disulfonated products is observed at higher 50;: olefin ratios. Disulfonation may be reduced by carrying the sulfonation reaction only to partial conversion of the olefin; for example, by using olefin ratios of less than 1 and removing the unreacted olefins by a dcoiling process. The unreacted olefins may be removed by extracting the reaction product with a hydrocarbon such as pentane.

In order to obtain a product of good color, the 80;, employed in the sulfonation reaction is generally mixed with an inert diluent or with a modifyig agent. Inert diluents which are satisfactory for this purpose include air, nitrogen, S0,, dichloromethane, etc. The volume ratio of S0, to diluent is usually within the range of H00 to l:l.

The reaction product from the sulfonation step may be neutralized with aqueous basic solutions containing sodium, potassium or ammonium hydroxides, carbonates, or oxides. In the preferred method, sufficient neutralizing solution may be added to provide for neutralization of the sulfonic acids formed by sultone hydrolysis. Generally, one equivalent of base for each mole of S0, consumed in the sulfonation reaction is added to the sulfonation reaction product. The proportion of hydroxyalkane sulfonates to alkene sulfonates in the hydrolyzed neutralized product may be varied somewhat by the manner in which neutralization and hydrolysis are carried out. Thus, reduced amounts of hydroxyalkane sulfonates are obtained by carrying out the neutralization and hydrolysis at temperatures in the range of l45-200 C., while higher yields of hydroxy sulfonate are favored by carrying out the neutralization and hydrolysis at temperatures below C.

Suitable hydrolysis temperatures range from about l-200 C.

The hydrogenated olefin sulfonates described above are very good lime-soap dispersants. That is, compositions of soap and hydrogenated olefin sulfonate give less insoluble curd in hard water than does the same soap alone. Any amount of the hydrogenated olefin sulfonate is beneficial in reducing curd formation. Thus, the amount 50% hydrogenated olefin sulfonate ranges upwards from about 1%, but preferably in excess of 5% of the total weight of soap and hydrogenated olefin sult'onate. As the quantity of hydrogenated olefin sulfonate in the combination bar is increased, the amount of insoluble curd that forms when the composition is dissolved in hard water is decreased. At soap to hydrogenated olefin sulfonate ratios less than about 85: I5, no curd is formed even in water containing 300 p.p.m. of hardness. It is generally preferred that the combars of this invention contains from -50% (by weight based on the two components) of hydrogenated olefin sulfonate.

Example 1: Preparation of Sodium Olefin Sulfonates The reactor used for this sulfonation consisted of a continuous falling film-type unit in the form of a vertical waterjacketed tube. Both the olefin and the SO,-air mixture were introduced at the top of the reactor and flowed concurrently down the reactor. At the bottom, the sulfonated product was separated from the airstream.

The feed was a straight'chain l-olefin blend produced by cracking highly paraffinic wax and having the following composition by weight: l% tetradecene, 27% pentadecene, 29% hexadecene, 28% heptadecene, l4% octadecene, and 1% nonadecene. This material was charged to the top of the above-described reactor at a rate of 306 pounds/hour. At the same time 124.2 pounds/hour of SO, diluted with air to 3% by volume concentration of S0, was introduced into the top of the reactor. The reactor was colled with water to maintain the temperature of the effluent product within the range of 43-46 C. The average residence time of the reactants in the reactor was less than 2 minutes.

After passing out of the reactor, the sulfonated product was mixed with 612 pounds/hour of 11.2% aqueous caustic and heated to l45l50 C. in a tubular reactor at an average residence time of 30 minutes. This step neutralized the sulfonic acids contained in the sulfonation reaction product, hydrolyzed the sultones to hydroxyalkane and alkene sulfonic acids, and neutralized these sulfonic acids. Olefin sulfonates were produced at the rate of 463 pounds per hour as an aqueous solution having a 45% by weight solids content and a pH of I08.

A portion of this product was analyzed and shown to be made up of the sodium salts of alkene sulfonic acids, hydroxyalkane sulfonic acids. and disulfonic acids. These three major components were present in a weight ratio of about 50:35: I 5.

Example ll: Preparation of Hydrogenated Sodium Olefin Sulfonates The apparatus for this hydrogenation consisted of a l-liter M agne-Drive autoclave equipped with an accumulator, a constant pressure regulator, and a temperature recording means. The product of Example I was diluted with water to a 26% solids concentration and was filtered to remove a trace amount of insoluble material. The pH was adjusted to a value of 6.5-7.5 by neutralizing the slight excess of NaOH used in the neutralization and hydrolysis step with H,SO,. One hundred parts of 30% hydrogen peroxide was then added to 3850 parts of the filtered 26% solution in an open glass vessel. This mixture was heated to 80 C. and stirred for l hour at this temperature, after which time no hydrogen peroxide remained. After cooling this solution to room temperature, 650 g. of it were charged to the previously described autoclave along with 8.5 g. of Raney nickel. The system was purged with nitrogen and then with hydrogen. It was then pressured with hydrogen to 50 p.s.i.g. The autoclave was warmed to 100 C. at which temperature hydrogen was again introduced to bring the pressure up to l00 p.s.i.g. and then vigorous stirring commenced. The hydrogen pressure was maintained constant at 100 p.s.i.g. throughout the run. After 1% hours of stirring at this temperature and pressure, and at which time there was no additional hydrogen uptake, the solution was cooled to about 70 C., filtered, and then allowed to cool. After cooling, the final product was drum dried.

Example ll]: Preparation of Combars I g. of commercial raw tallow soap (a mixture of sodium oleate, palmitate and stearate (containing about 10% water and 40 g. of the product of Example ll were dissolved in 600 ml. of hot distilled water and then drum dried to about 4% water content. The resulting soap-detergent mixture was milled on a conventional milling apparatus and enough water was added during this milling operation to permit the composition to be milled into ribbons. The composition was then formed into bars using a conventional soap bar mold. The bars formed in this way were about 2% inches by 1% inches by as inch in size. They were stored for one week at ambient temperature and humidity. At the end of this time the bars weighed 26-27 grams and contained 5.6% water.

Another bar was prepared in essentially the same way as before but with a 60:40 ratio of soap and hydrogenated olefin sulfonate. Both bars were tested for handwashing by a panel and were found to have excellent soap-type feel," to form good lather, and to remove body soil satisfactorily.

The compositions of this invention were next tested for curd formation in 300 p.p.m. hard water (2/3 calcium and H3 magnesium chlorides). In this test, one part of the soaphydrogenated olefin sulfonate composition was dissolved in 99 parts of distilled water. Then 10 ml. of this 1% solution and ml. of 334 p.p.m. hard water were added to a 100 ml. stoppered graduate and well mixed. After sanding for 5 minutes, the volume of insoluble lime-soap curd was measured. The results of this test are given below:

Soap/H ydrogenated Olefin Sull'onate Ratio Curd, ml.

l00/0 5 90/ l O 1.5 80/20 0 70130-50150 0 All of the above examples were prepared by formulating a mixture of the correct amount of the sodium hydrogenated olefin sulfonates of Example 11 and tallow soap.

While completely satisfactory bars can be prepared from hydrogenated olefin sulfonates as shown above, the feel and appearance of the bars may be further improved by incorporation of conventional emollients, superfatting agents, opacifiers, fillers, perfumes, dyes, and the like. These additives may constitute up to about 40% by weight of the finished bar. Representative conventional additives are the polyethylene glycols, C -C fatty alcohols, stearic acid, mineral oil, fatty acid amides, mixed fatty acid alkanolamine compounds, lauric-isopropanolamide, polyethylene glycol monostearates, and glycerol monostearate.

In addition, it may be desirable to have incorporated within the soap/synthetic detergent combar other detergent-active materials compatible with the hydrogenated olefin suli'onates in an amount of from 0-25% by weight of the hydrogenated olefin sulfonates. Such detergent-actives would include straight-chain alkylbenzene sullonates, straight-chain primary and secondary alkyl sulfates, polyoxyethylene alkylphenol sulfates, acylisethionates, alkyl glyceryl ether sulfonates, and sulfated fatty acid monoglycerides.

While the character of this invention has been described in detail with numerous examples, this has been done by way of illustration only and without limitation of the invention. It will be apparent to those skilled in the art that modifications and variations of the illustrative examples may be made in the practice of the invention within the scope of the following claims.

1. Soap and detergent bars consisting essentially of a major proportion of one or more water soluble soaps of fatty acids having from about to carbon atoms and a minor proportion of C -C, hydrogenated olefin sulfonates sufficient to retain in suspension the insoluble lime soaps resulting from use of the soap and detergent bars in hard water.

2. Soap and detergent bars as in claim I, wherein the hydrogenated olefin sulfonates are derived from alpha olefins.

3. Soap and detergent bars as in claim 2, wherein the water soluble soaps of fatty acids comprise a mixture of sodium stearate, sodium oleate and sodium palmitate.

4. Soap and detergent bars as in claim 3, wherein the hydrogenated olefin sulfonates contain from about 25 to 75% by weight alkane sulfonates, from about 25 to 65% by weight hydroxyalkane sulfonates, and not more than about 20% by weight disulfonates.

5. Soap and detergent bars as in claim 4, wherein the cation in the hydrogenated olefin sulfonates is sodium.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,607 ,766 Dated September 21, 1971 Inventor) Gar Lok woo and William Alan Sweeney It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, lines 70-71: "12 to 18," should read -l2 to 18,

carbon atoms.--

Col. 2, line 30: "l b-250C." should read --l l525OC.--

Col. 2, line U2: "S0 should read --SO Col. 3, line 8: "amount 50%" should read -amount 019-- Signed and sealed this 21st day of March 1972.

(SEAL) Attest:

ROBERT GOTTSCHALK Commissioner of Patents EDWARD MxPLETcHERQ JR. Attesting Officer 

2. Soap and detergent bars as in claim 1, wherein the hydrogenated olefin sulfonates are derived from alpha olefins.
 3. Soap and detergent bars as in claim 2, wherein the water soluble soaps of fatty acids comprise a mixture of sodium stearate, sodium oleate and sodium palmitate.
 4. Soap and detergent bars as in claim 3, wherein the hydrogenated olefin sulfonates contain from about 25 to 75% by weight alkane sulfonates, from about 25 to 65% by weight hydroxyalkane sulfonates, and not more than about 20% by weight disulfonates.
 5. Soap and detergent bars as in claim 4, wherein the cation in the hydrogenated olefin sulfonates is sodium. 